Mandrel



Patented Oct. 9, 1928.

RATEMZ ronns'r r. ,FILLQON'; OF MINNEAPOLIS; MINNESOTA, ,ASSiGIfIOR-TQ INNESOTA; Minn e Ann MANUrAoTURIN-G ooMrAnY, on; ST.-- PAUL; MINNESQTA; A joonl-vonerron or} MINNESOTA.

' MANDRELJ- Application mum 1 1 25-51 r flliflqniifilflo My invention relates to dental mandrels wherein it is desired to providea mandrel for holding the dental disks in; a-nianner so that when in usethe disks-wilhnothecome loose accidentally or by the vibration in the opera-- tion of the mandrel while the dentist is orking on onels teeth. While; somemandrels are designed to prevent loosening got: {the disks when in use by thewdentist yetthey do "not.

10 have the positive-locking meanis v:Whichis adapted to hold the di'skholding pin looked in position while in use-until it is released by a separatemanualpperation, as: I have defsigned my mandrel to operate- A feature of the, invention ;resides duga dental mandrel wherein-a clutching jaw ac tion is provided which engages the pin of-the disk holding headtofirmly grip the same and Y prevent it from disengagement until-thelock- 2O ing collar. is released on :themandrel proper.

Itis alsoa feature ofthe inventiongtoiprovidea disk engaging pin whichisadapted to hold thedisk against .rotating-in'relation to the inandreland .causing the same .to rotate with the mandrel in operationiz I have designed a simple effective mandrel which is particularly adapted :toholdpolishing and grinding disksv for. dental purposes,

such'iasthinpaper 'or suitably prepared disks 0 with'a grindingisurface oni onesiden This grinding surface is held .in'the mandrel :to-'

ward the inner side, ordinarily,:.and my .invention includes means for holding the. disks so. that. it Will not work itself loosein .the op- 'eration of the dentalclutch which rotates the mandreland disk;1andthusthe-diskjisheld so tightly in my mandrelthatuit can beentirely torn-away without the disk :holding :elutch means becoming loose, leaving-the portion of 40 fthe disk'firinly clampedin mymandrel head whichwould be torn from the centerlof the same .ifforce enough is exertedfagainstthe These features together with other objects and detail'sof construction willlbe more .fully setforth in the specification and claims.

In the drawings forming part oft-hisspeeification; I

Figure 1' is a side yiewaof my mandrel: as it would appearin use partly illustrated ;in cross. section. c

FigureQ isa sideview ef my mandrel,:pa-rt-. ly-illustrated in:cross,-section with the disk holding pin and'headrenlovedu; v

Figure 3 is aside .vi-ewofi the mandrel rod with the. locking c'oller :remoyed. from the same. a

Figure {Lis an'endyie-w of theimandrel rod showing he s d omtrnctioniof the! same Figure 5 isa crosssectional:side view'ofithe locking eollar removed from the mandrel rod.

I Figurefi illustratesnt-he. disk pin removed hei andreh; 1 .1 a

igu e- 7 is anpend \i' wenithe'1ine.-7';+7 of Figurefim, Y I

' Figure- 8 l'illustrates en alternatiye fOI'mEOf hemendre rodm Figure 9 anendyviewiof the illu tratediniFigurei8. r* I I Figure 10 ,is; the disk;.:pin {used with the ,mandrfel'rod:illustratedin Figure 81 1 mandrelirod gll ev r i l tratesnn zordinary'eirc-ular en alisk-i I Inlthe .drawings;,1.-the.mandrel:A "is formed with a mandrelrod :10 which isprovidedwith a hank/110th rod-like natnraiwh-ichfits into theuhaind iclutch, not illustrated intherdraws velopingi my. mandrel; so. that tit will be :most

practical Gfor; use .in': thee ordinary standard dental'hand-clutehL Theishankll 'fitsrfinto thisaclntoh and :is. lockedfirm-lyt therein Kill the .ord-inanv andiwellknown manneri;

The mandrel rod; 10 :is formedof a suitable lengthv and is provided with a tapered end porti0n1=12 which is. formed with aniannular shonlderlS nnthe innenenlalrgedendland the outer edge .14! is. slit at.-15tto .proyide: gripping j awe-164i. i

' The-.slits :15 extend ilongitudinally into the form a recess or hole 17 extendingiback into the rod zsl-ightly .beyond5the..-1ength of the slits 15, the =slits==15 .extendingdhmugh into -.mandr.elr0d\.10zand thexrodoiO isdrilled to i I the zopening'. or. holed? -Tnis', provides: the

gripping jaws 16 with suitable flexibility to permit them to be compressed together and of such anature as to spring apart into open position when the tapered end 12 is not compressed together. In this manner I provide spring gripping jaws 16 which are adapted to operate as will be hereinafter described.

A locking collar 18 having a tapered inner recess 19 which is adapted to conform with the taper of the end 12 of the mandrel rod 10, is adapted to be placed. over the portion 12 of the rod and is headed or turned in at 20 to form an annular shoulder which is adapted to engage the annular shoulder 13. The recess 19 of the collar 18 is somewhat longer than the length of the portion 12 of the rod so that after the shoulder'20 is formed on the locking collar 18, the collar can be movc'l back and forth over the head or tapered end 12 of the mandrel 10 to cause the tapered recess 19 of the collar to compress or release'the U jaws 16 of the mandrel A.

The collar 18 is so formed that when it is moved into backward position, the gripping jaws 16 will be compressed tightly together and the collar will firmly lock the aws in this position. The collar 18 engages the jaws 16 frictionally so as to firmly and rigidly hold the jaws inclosed position, as illustrated in Figure 1. When the collar 18 is engaged and pulled outward into the position illustrated in Figure 2, the gripping jaws 16 are released and expand into open position.

The dental disk 22 illustrated in Figure 11 is formed with a cutting or polishing surface 23 on one side and is provided with an opening 2a in the center of the same so that it canbe attached to the mandrel A.

I provide a disk holding pin'B which is formed with a round disk like head 25 and a tapered pin'26 secured to and extending from one side of the same. This pin 26 is tapered or wedge shaped so that the outer free end 27 of the pin is enlarged, while the inner end 28 which connects with the head 25 is small in diameter, and in fact the pin is almost conical shaped. It is desirable that the pin 26 is of a-shape' to simulate the taper of the portion 12 and the recess 19 of the collar 18.

The enlarged end 27 of the pin is provided with an outwardly projecting key portion 29 which is adapted to engage in one of the slots of the mandrel rod 10 when the pin 26 is inserted into the opening 17 of the same. This holds the pin 26 with the head against rotation when the same is placed in engagement with the recess in the mandrel rod 10. The key 29 fits into the lower extremity of the slots 15 and this portion of the slots is not compressed like the outer end of the edge 14: of the mandrel rod. r

The disk holding pin B is provided with disk engaging prongs 30 which may be out from the body of the head to form little sharp prongs 30 which engage and penetrate through the disk 22 when the disk pin B is I passed through the center opening 24: in the disk, so as to firmly engage the dental disk 22 and rigidly clamp it to the mandrel A. I provide a recess 32 in the collar 18 to receive the points of the prongs 30 and to protect the same when the disk pin is attached to the mandrel rod 10.

In operation the pin B is removed from the mandrel A, as illustrated in Figure 2 and in Figure 6, then the disks 22 can be slipped over the pin 26 of the disk holding pin B and with the collar 18 engaged by the fingers of the operator and held in released position, the pin 26 is inserted into the opening 17 with the key 29 engaging in one of the slots 15. As the pin 26 is pushed into the hole 17 whenthe prongs 80 have pierced the disk 22, the collar 16 is permitted to operate back on to the head 12 and to frictionally engage the same, which is formed with a long taper, as illustrated, so as to lock the disk 22 firmly and rigidly to the mandrel A. Simultaneously with this operation the pin 26 is wedged and locked tightly in the opening 17 by the compression of the jaws 16 about the same to lock and firmly hold T the pin against movement. This operation can be carried out either when the mandrel rod 10 is held in the dental hand clutch or when it is out of the same so that the dentist can readily and quickly place the disk rigidly attached to the mandrel A. In fact, the oper ation is so simple and effective that in practical use I have found that my mandrel is to be preferred for its simplicity and effectiveness in operation.

When the disk 22 is held in this manner as illustrated in Figure 1, locked to the mandrel A, it cannot come loose in operation either by the rotary movement of the mandrel or the vibrations in operation, and as the pull on the disk 22 is in the direction of the arrow illustrated in Figure 1 against the inner surface 23 of the disk, itis quite important'to' consider that my mandrel isvery effective in operation. When the dentist desires to replace the old disk22 with a new one it is only necessary for him'to engage the collar 18 and pull slightly outward on the same, the annular shoulder 20 limiting the movement of the collar in coming in engagement with the shoulder-13, and when in this position. as illustrated in Figure 2, the pin B with the old disk 22 can be easily removed and a new disk inserted in place over the pin B. This operation is quick and effective and thus I provide a dental mandrel which is very desirable'in practical use and which is meeting with marked approval of the dental profession.

construction I provide the diskholding pin C which is similar to the pin B with a flat pin shank 26 which fits into the slot 15 of the rod 10 in the same manner as the round pin 26 fits in the-opening 17, In this construction it is not necessary to provide a key 29 as the flat nature of the pin 26 is suficient to hold the disk engaging pin C from rotating. As in this construction the collar 18 is of the same formation and operates exactly in the same manner to release the pin C as is true of the operation of the pin B in the mandrel A. Thus in practically every respect the mandrel rod 10 in Figure 8 with the pin C in Figure 10 operates as is true of the mandrel illustrated in Figure 1 to hold the disks 22 in locked position until the collar 18 is released on the taper end 12.

In accordance with the patent statutes I have described the principles of operation of my dental. mandrel and while I have illustrated a particular formation of the same in the drawings, I desire to have it understood that these are only suggestive and that the invention can be carried out by other means and applied to uses other than those set fort-h within the scope of the following claims.

I claim: 1. A dental mandrel consisting of a hollow rod, split jaws to form grippers, a tapered outer surface on said aws converging toward the end of the rod upon which the aws are placed, an annular shoulder on said rod, a collar having a hollow tapered core adapted to cooperate with the tapered surface of said jaws to compress the same, shoulders formed on said collar adapted to engage the annular shoulder on the rod for limiting the movement of said collar with relation to the jaws and a disk supporting tapered pin and head adapted to be locked or released by said collar operating to engage said jaws.

' 2. A- dental disk holder comprising, a hollow rod, tapered gripping jaws formed on said rod, a disk holding member having a head portion and a pin adapted to be engaged by said jaws, and disk piercing points formed on said head, a collar for contracting said jaws, said collar having a recess formed in its head for the reception of the disk piercing points. 

